Friday, August 21, 2009
Over the last few days, several people have called (in a panic) to ask me what is covering their trees. They describe a ghostly sheath that envelops the branches and trunk. "Spooky" is the adjective that everyone seems to use when describing this phenomenon.
The fine webbing is spun by tiny insects called psocids- commonly called bark lice or tree cattle (I prefer the latter). They spin their webs over the bark to protect themselves from wind, weather and predators. Under this silk stocking, the tree cattle "graze" across the bark's landscape feeding on lichens, fungi and debris.
Tree cattle are beneficial insects, cleaning off the tree and helping it be healthy. Expect to find them on hardwoods like Magnolia and Oak from about mid-August to October.